A little background on how I started Roof Sparkle. A company that’s making cleaning products asked me if I could make a video for some of their cleaning products. Now I won’t go into details on who they are but they had a roof cleaner that involved the use of a power washer. A big red flag in my eyes. Being a contractor for years, I knew right off the bat that was a big no-no.
So the next question I asked myself what’s that black stuff on the roof. Well, it’s mold. And what kills mold, bleach right. Well, as true as that is bleach is only made up of 5-6% Sodium Hypocrite. And that’s great for your whites and around the house but not on your roof.
For the roof, you will need something a lot more powerful. Some of you may know it as pool shock. This is made up of 12% by weight “Sodium Hypochlorite”. But because it’s as thin as the water it will run right off the roof and not really have the time (five minutes) to do its job. So we have to thicken up a bit. The best way, add some liquid dish soap to the mix to help the SH stick to the roof for more than one second. You can go into any pool supply and ask for a gallon of shock, for about $4.00 per gallon. This is just a heavy-duty version of household bleach. And no Walmart does not sell this or the big box stores. This method will remove algae from a roof.
Now, of course, we buy it from the manufacturer and by the truckloads at a time.
Applying It
When we started we used a regular bug sprayer. Use a three gallon pump sprayer, use one gallon of SH and two gallons of water (H2O) add about 4 oz. of liquid dish soap and spray from the roof top working your way down.
DON’T
- clean your roof when it’s super hot out in the baking sun. It will kill the SH and dry before it’s clean.
- Don’t touch the SH with bare hands. Wear gloves and eye protection.
- Don’t spray your roof down first with water to cool it off.
Comments ( 173 )
What kind of dish soap is the best to use?
Thank you.
Any good thick one without bleach in it.
I have a composite deck at the base of my roof area I’ll be treating. The deck also has mold from it being on the north side. Will this solution be okay on the decking material? It’s like a trex deck but not that brand. Actually, forgot the name. duh! Can I try it on my front small wood deck to clean off the black from years of it sitting? Normally power washing would be done on it. I’m selling my home and the realtor gave me things to do to prepare it for a buyer. The poconos in PA is woodsey and while it’s beautiful, it’s also requires maintenance. Thanks Dom.
Hi, sorry for the delay. Your question came in as spam for whatever reason..
The SH wont harm the deck but clean it very well. I’ve used it with a big mop before and it came out great. But then again, that was for me. The Poconos ?. Heck we’re not that far apart at all. I’m there almost every weekend.
Hello Dominic first of all great site and thanks for all the help. Second I am having trouble finding a 3 gallon pump sprayer and if I do find one it is either bigger or expensive so I was going to get a 2 gallon one if that would work. Any idea how much shock and water and dish soap to use to get the mixture right. I got the 12.5 shock from pool place I have the The dish soap and water but I don’t know ratios go the 2 gallon pump sp5rsyer. I figured I would run it by you see what you thought or if you had another idea
It really depends on how bad the roof is. If it’s really bad you could do 50/50 But no. The smallest I know is 1/3
great site Dominick! I live in central Canada where it is now 10C-15C during the daytime. It gets close to 0C at night.
I plan on applying your solution to my roof this weekend. questions: Do I need to rinse it off, or just wait for mother nature to do her magic with rain? Will the strength of the SH just dissipate over time and not harm my grass if I leave it on the roof without rinsing? If I do have to rinse, how long do you leave the SH on before the rinse? Can I use cold water from the tap?
I am a lady afraid of heights trying this myself, so the least amount of time on the roof the better!! Thanks.
Yes to a extent, but you wouldn’t want it to dry on the roof. So rinsing it is always a better choice.
Thanks for the great info, Dominick! I’m looking forward to trying this out. One question though – I have a bottle of Sunlight dish soap that says on the back ‘do not mix with chlorine bleach’, but my bottle of Dawn does not say that. The warning on the first has me worried though! What brand have you used? Have you ever used Dawn? I’d hate to have some I intended chemical reaction! Thanks.
Yes we use Dawn most of the time. But remember you’re not using the soap to clean. It’s only there to help hold the SH on the roof longer rather than being too thin and just running right off.
I just did my siding on the north side of my house, using Dawn liquid and a 4 litre sprayer. I have never seen my siding look so great since the day it was installed! Thanks so much. I’ve tried scrubbing some of the stains before with different products, to no avail. I can’t believe this was so easy. The only unintended consequence is that my wood deck underneath is now really clean where the runoff was, so I’m going to spray the whole thing. This works out really well, as I need to re-stain it anyway. I can’t wait to try this on the roof. I had a quote to get my shingles redone and it was going to be $4000, when really there’s nothing wrong with them other than black streaks. This is a much better way to go, and saves my wallet. Thanks again!
Dominick,
Thanks for the great information on the moss removal. There is so much information available on the net I really appreciate your straight forward approach and advice. I am trying to decide between your method or using oxygen bleach cleaners with sodium percabonate & soda ash. Have you ever used these types of cleaners? Also what do you recommend for preventing moss from coming back?
There is no option when it comes to SH and Oxygen bleach. SH is the only way. And no, I’ve tried everything. Either too dangerous or they just don’t work.
Look for my video on how to prevent moss. You would use copper flashing.
Great videos and Q&A info…outstanding Dominick.
Can we use a 5 gallon bucket & Wayne PC2 115-Volt 340 GPH Portable Transfer Water Pump, Bronze to send your mixed 3 gallon solution up onto the roof without having to climb up on the roof? I am not enthusiastic about climbing up on the roof.
Thank you so much. Is the pressure is there sure. However the SH will rust out the pump in no time. So make sure you clean it with water afterwards.
Hi there
I am getting ready to do my shingle roof in florida and I want to know if I can use a 50/50 solution of liquid chlorine and water and then, add the dish soap. By the way, the tank I rented to mix it all up is 50 gallons. so how much dish soap should I use. any help would be great.
Thanks
Rick
Yes you could use 50/50 of SH and water. 50 gallons I use a small size to 50 gallons. Dawn works the best.
I just did my roof today using pool chlorine 1 part and water 2 parts. Soaked the roof with pump sprayer and kept it wet with garden hose misting it. Im in FL and it is hot and sunny today. All the dark brown and black rinsed off in few minutes like you said. Quick and easy process.
Yesterday I tried Krud Kutter I bought at Lowes – $25 for two gallons. That stuff stained my shingles brown and did not work at all. Your method fixed everything. Thank you for great advice.
G
Awesome, glad I could help you out.
What if you apply your mix to roof and get a surprise rain? What happens to plants with run off? Even if you soaked during or prior. Also, not having the gutters to bag to protect them. Here in Florida it happens a lot. Sometimes can rain in the back yard and not in the front yard.
No biggie really. As long as it’s a good rain and rinses it well you should be fine.